flexmeasures.data.schemas.units

Classes

class flexmeasures.data.schemas.units.QuantityField(to_unit: str, *args, default_src_unit: str | None = None, return_magnitude: bool = False, **kwargs)

Marshmallow/Click field for validating quantities against a unit registry.

The FlexMeasures unit registry is based on the pint library.

For example:
>>> percentage_field = QuantityField("%", validate=validate.Range(min=0, max=1))
>>> percentage_field.deserialize("2.5%")
<Quantity(2.5, 'percent')>
>>> percentage_field.deserialize(0.025)
<Quantity(2.5, 'percent')>
>>> power_field = QuantityField("kW", validate=validate.Range(max=ur.Quantity("1 kW")))
>>> power_field.deserialize("120 W")
<Quantity(0.12, 'kilowatt')>
__init__(to_unit: str, *args, default_src_unit: str | None = None, return_magnitude: bool = False, **kwargs)
_deserialize(value, attr, data, return_magnitude: bool | None = None, **kwargs) → Quantity

Turn a quantity describing string into a Quantity.

_serialize(value, attr, obj, **kwargs)

Turn a Quantity into a string in scientific format.

class flexmeasures.data.schemas.units.QuantityValidator(*, error: str | None = None)

Validator which succeeds if the value passed to it is a valid quantity.

__init__(*, error: str | None = None)
class flexmeasures.data.schemas.units.UnitField(*, load_default: ~typing.Any = <marshmallow.missing>, missing: ~typing.Any = <marshmallow.missing>, dump_default: ~typing.Any = <marshmallow.missing>, default: ~typing.Any = <marshmallow.missing>, data_key: str | None = None, attribute: str | None = None, validate: ~typing.Callable[[~typing.Any], ~typing.Any] | ~typing.Iterable[~typing.Callable[[~typing.Any], ~typing.Any]] | None = None, required: bool = False, allow_none: bool | None = None, load_only: bool = False, dump_only: bool = False, error_messages: dict[str, str] | None = None, metadata: ~typing.Mapping[str, ~typing.Any] | None = None, **additional_metadata)

Field that represents a unit.

_deserialize(value, attr, data, **kwargs) → str

Deserialize value. Concrete Field classes should implement this method.

Parameters:

  • value – The value to be deserialized.

  • attr – The attribute/key in data to be deserialized.

  • data – The raw input data passed to the Schema.load <marshmallow.Schema.load>.

  • kwargs – Field-specific keyword arguments.

Raises:

ValidationError – In case of formatting or validation failure.

Returns:

The deserialized value.

Changed in version 3.0.0: Added **kwargs to signature.

_serialize(value: str, attr, obj, **kwargs) → str

Serializes value to a basic Python datatype. Noop by default. Concrete Field classes should implement this method.

Example:

class TitleCase(Field):
    def _serialize(self, value, attr, obj, **kwargs):
        if not value:
            return ""
        return str(value).title()
Parameters:

  • value – The value to be serialized.

  • attr – The attribute or key on the object to be serialized.

  • obj – The object the value was pulled from.

  • kwargs – Field-specific keyword arguments.

Returns:

The serialized value